Predicting the forces in a neck injury caused by an underwater collision

The injuries caused to the neck of a man diving into a lake. Based on the reconstruction of the accident it appeared that his head struck a PVC (polyvinyl chloride) pipe - no other objects were present. The possibility that the collision was with the lake bottom was considered unlikely because of the angle and the resulting injury. It is found that the forces required to cause the injury suffered by the patient were not well predicted by the simple engineering calculations that ignored the effects of the water environment. The calculations indicated that the pipe would be damaged prior to the onset of an injury. No damage to the pipe was observed in the actual accident. The experiments that modeled the accident showed that the effect of the water was to increase forces and protect the pipe from damage during the onset of these forces. Various criteria for the onset of neck injuries were calculated based on the experimental data. These criteria included steady state values of maximum force and the more sophisticated N_ij proposed by the NHSTA (National Highway Safety Transportation Agency). Rate dependent measures were ignored in this study.